v16.2.15
admin/build-doc: s/virtualenv/python3 -m venv/
admin/build-doc: consolidate the build deps into admin/doc-pybind.txt
doc: build mon_command_api.rst using a homebrew extension
ceph/admin: s/master/main
admin/doc-requirements: bump Sphinx to 5.0.2
admin/serve-doc: Switch to python3 only